Bet on chance

Published December 7, 2009 by Benjamin Tseng

When people think about strategy, they’re oftentimes looking for that one “silver bullet” which is the 100% correct and best answer. This is despite the fact that it is sometimes 100% valid to use random chance to make a decision.

Well, it turns out that bacteria have figured this out as well, as researchers have recently reported in Nature (HT: Wired Science). The researchers did a fascinating experiment where they forced bacteria to cope with a rapidly changing environment. Normally, you would expect that, if bacteria were forced into a different environment, the population as a whole would “evolve” to acquire the traits that are necessary to survive in that environment. And, at first, this is what the researchers observed – the shifts in environment “drove the successive evolution of novel phenotypes by mutation and selection.”

But, after a while, something very interesting happened – some of the bacterial populations (roughly 1 in 12) “recognized” that they were being put through the ringer and evolved a “gambling” strategy (the researchers called it a “stochastic switching between phenotypic states”) whereby individual bacteria would actually pick a strategy at random! “Knowing” that they were in a constant state of environmental flux with little predictability, these populations of bacteria evolved an ability to have individual bacterium pick random strategies such that genetically identical bacterium would end up with very different traits!

Many people, let alone bacteria, find the idea of a random strategy as a winning one to be counter-intuitive. But, the ability of even the simplest creatures to re-capitulate proves that randomness can not only be effective, but its possibly how the earliest living things coped with a very strange and rapidly changing environment.